Sorlie Memorial Bridge
Introduction
Text-to-speech Audio
Images
The original schematics for the "Roller Bearings."
The "Roller Bearings" underneath the bridge.
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The bridge pictured in 2006.
Backstory and Context
Text-to-speech Audio
Early History
The Sorlie Bridge was built in 1929 with help from federal aid money provided by The Bureau of Public Roads. The bridge was one of the first urban projects in the country to use these funds. Notably, the bridge was a replacement for a swing bridge which had been built at the site in 1889. By 1929 this older bridge was severely outdated.
The bridge crosses the Red River from Grand Forks, North Dakota, to East Grand Forks, Minnesota. The river itself serves as the state line in this area. When it was originally constructed, the bridge served as the sole motor river crossing in the immediate area. This was vital for travelers wishing to drive from North Dakota to Minnesota via U.S. Highway 2.
Construction
The bridges’ construction consists of a rigid Parker truss with a steel superstructure. The Parker design was extremely popular in bridge building during the early and mid-twentieth centuries. This design is identified by the large vertical members on the bridge, which are built to handle the stress of the bridge road they support. These members (or pillars) are supported by a polygonal chord, which give the bridge its recognizable “humped” look. Overall, the bridge is approximately 605 feet long, with a deck that is 60 feet wide.
When the bridge was originally constructed, there was a concern that shifting ground on the banks of the Red River made the site unsuitable for traditional abutments (the supports on either end of the bridge). Originally, rock foundations were considered, but these proved too costly. The solution came from department bridge engineer Clifford Johnson, who envisioned large “roller bearings” that would shift with the weight of the bridge as the ground moved. These bearings proved to be sturdy, cheap, and revolutionary for bridge construction at the time. It was the first bridge in the United States to use this design.
Dedication
The bridge is dedicated and named after Arthur G. Sorlie, a past governor of North Dakota and ex-officio Chairman of the State Highway Commission. During his terms as governor, Sorlie was known for his sweeping reforms in the State Highway Department. These reforms allowed the state of North Dakota to quickly build good quality roads across the state in both a cheap and timely manner. Due to these reforms, Sorlie became known as “a true friend of better roads and bridges.” This moniker is depicted on a commemorative plate attached to the bridge.
Sources
Minnesota Department of Transportation. Historic Bridge Management Plan, Bridge Number: 4700. http://www.dot.state.mn.us/historicbridges/bridge/4700/management-plan2006.pdf
Minnesota Department of Transportation. Minnesota Historic Property Record (Bridge 4700). http://www.dot.state.mn.us/historicbridges/bridge/4700/property-record.pdf
U.S National Parks Service. National Register of Historic Places and National Historic Landmarks. North Dakota MPS Sorlie Memorial Bridge. https://catalog.archives.gov/id/75326127
Quivik, Fredric L. et. al. Historic Iron and Steel Bridges in Minnesota, 1873-1945. National Register of Historic Places and National Historic Landmarks, 1988. http://www.dot.state.mn.us/historicbridges/bridge/4700/historic-context.pdf
Sorlie Memorial Bridge (Bridge 4700), Minnesota Department of Transportation. Accessed April 19th 2021. http://www.dot.state.mn.us/historicbridges/4700.html.